And before you go mounting the HD7698P antenna higher you can try the HD7698P antenna on the same mast as the other antenna.
Put the HD7698P antenna on the bottom and have the antennas separated by about 3 feet if you can on the same mast.
Try the HD7698P antenna with out a preamp first and if signals need a little more umph to keep them locked in then use a Antennas Direct CPA-19 preamp with the HD7698P antenna.
The HD7698P antenna is aimed at about 177 degree magnetic compass.
Here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html.